Short answers, pulled from the story.
Vitruvius was a Roman architect and engineer who lived from approximately 80-70 BC to sometime after 15 BC. He served as a military engineer under Julius Caesar, specializing in ballista and scorpio siege machines, and is the author of De architectura, the only major architectural treatise to survive from classical antiquity.
De architectura, known as The Ten Books on Architecture, is a multi-volume Latin treatise dedicated to the emperor Augustus. It covers building design, city planning, construction materials, aqueducts, surveying instruments, machines, and the proportions of the human body, arguing that all structures must exhibit firmitas, utilitas, and venustas: strength, utility, and beauty.
De architectura was rediscovered in 1414 by the Florentine humanist Poggio Bracciolini in the library of Saint Gall Abbey. Leon Battista Alberti then publicised it in his own architectural treatise around 1450, and the first printed Latin edition appeared in Rome in 1486.
The Vitruvian Man is Leonardo da Vinci's famous drawing of the human body inscribed in a circle and a square, based on proportions Vitruvius described in Book III of De architectura. Vitruvius wrote that the human figure was the principal source of architectural proportion, a concept later illustrated by da Vinci and other Renaissance artists.
The only confirmed building by Vitruvius is a basilica completed in 19 BC at Fanum Fortunae, the town now called Fano on the Adriatic coast of Italy. Its remains were discovered on the 19th of January 2026 during archaeological excavations in Piazza Andrea Costa, Fano.
Vitruvius held that all buildings must exhibit firmitas, utilitas, and venustas, meaning strength, utility, and beauty. These three qualities are sometimes called the Vitruvian virtues or the Vitruvian Triad and are described in De architectura as fundamental requirements for any structure.